I have the same problems you all are having.
I have an Intel Centrino Wireless-n 2230
And my router is a Apple Time Capule.
The best I got was installing updated drivers without the Intel software. Had to find the temporary folder that the setup.exe creates, open it, install the drivers separated, and then close the setup without installing the PRO/Wireless tool.
Sometimes it goes for days without disconnecting. Maybe I'll try to find the factory drivers for Windows 8 over the Windows 8.1 version, which was quite stable on Windows 8.